Setting up uv on Discover

setting-up-uv-on-discover.md

Setting up uv on Discover

This setup keeps uv, its cache, managed Python installations, and tools on $NOBACKUP storage instead of in your home directory.

Configure uv

Add the following to ~/.bashrc:

export UV_ROOT="$NOBACKUP/uv"

export UV_CACHE_DIR="$UV_ROOT/cache"
export UV_PYTHON_CACHE_DIR="$UV_ROOT/cache/python"
export UV_TOOL_DIR="$UV_ROOT/tools"
export UV_PYTHON_INSTALL_DIR="$UV_ROOT/python"
export UV_TOOL_BIN_DIR="$UV_ROOT/bin"
export UV_PYTHON_BIN_DIR="$UV_ROOT/bin"
export UV_INSTALL_DIR="$UV_ROOT/bin"

# Use copies instead of hard links across filesystems.
export UV_LINK_MODE=copy

export PATH="$UV_ROOT/bin:$PATH"

Create the directories:

mkdir -p "$UV_ROOT"/{bin,cache,tools,python}

Reload the shell configuration:

source ~/.bashrc

Install uv

curl -LsSf https://astral.sh/uv/install.sh | \
  sh

Check that the installation is being used:

command -v uv
uv --version

The path should be inside $UV_ROOT/bin, for example:

$NOBACKUP/uv/bin/uv

Update uv

Because uv was installed with the standalone installer, update it with:

uv self update

The UV_INSTALL_DIR setting above keeps the updated executable in $UV_ROOT/bin.

Create a virtual environment

Choose a working directory on project or nobackup storage. The virtual environment itself should not be created under $HOME, since installed packages are stored in the virtual environment, not just in the cache:

mkdir -p "$NOBACKUP/uvtest"
cd "$NOBACKUP/uvtest"

uv venv

This creates a virtual environment in .venv. You can activate it with:

source .venv/bin/activate

Activation is optional. uv automatically detects a .venv in the current directory:

uv pip install PACKAGE_NAME

Replace PACKAGE_NAME with the package or packages you need.

To request a specific Python version, use for example:

uv venv --python 3.12

Managed Python versions are stored under $UV_PYTHON_INSTALL_DIR.

Check and clean the cache

The cache is useful, but it can grow over time. To see its location and remove unused cached data:

uv cache dir
uv cache prune

To remove the entire cache instead:

uv cache clean

See the uv documentation for more information.